The present invention relates to an electricity turning-on control device placed in a communication terminal unit, an OA device or the like, and to a facsimile device incorporating the electricity turning-on control device.
A facsimile device as a communication terminal unit conventionally has plural control sections including a main control section for controlling the operation of a driving section, an operation panel control section for controlling a switch for main-power source or the like, and a network control unit (hereafter, referred to as NCU) for controlling the operation of a communication line. The main control section controls an electricity turning-on operation of the driving section on the basis of the information from the operation panel control section. The main control section also controls input and output operations of data through the NCU.
The main control section of the facsimile device performs processing for storing received image data in a memory. The main control section also performs compressing, expanding and editing of the image data and further controls the operation of a printing section or the like. It is therefore necessary for the main control section to process a large capacity of image data at high speed. Accordingly, the main control section requires a central processing unit (hereafter, referred to as CPU) in which a clock frequency is high and which is capable of simultaneously processing a large number of bits.
However, if the CPU has the high clock frequency and is capable of simultaneously processing a large number of bits, power consumption required to operate the CPU is increased. For example, if the clock frequency of the CPU is 16 [MHz] and the simultaneously processed bit number is 32, an electric current of approximately 1 [A] flows through the CPU even in its standby state.
Further, since the power source section supplies electric power to the main control section, even in the standby state, electric power is consumed by heat from a transformer.
That is to say, in the conventional communication terminal unit, electric power is supplied to the power source section and each of the control sections even in the standby state so that there is a problem about useless consumption of power.
Moreover, if, in the standby state, the power source section, the supply of electric power to the main control section is turned off, the following problem occurs. When a predetermined detecting signal for starting the operation of the driving section is inputted to the main control section while the power source switch is in the electricity turning-off state, it takes a long time to establish a condition regarding an I/O interface of the main control unit.